This invention relates to sprinklers and, specifically, to a sprinkler that incorporates adjustable arc and/or adjustable flow rate features.
It is known to utilize interchangeable arc or other shaped nozzles in sprinklers in order to permit adjustment of the degree of coverage of the discharge stream, while maintaining a constant flow or precipitation rate in the watered areas. Typically, these nozzles comprise orifice plates which have a central hole for receiving a shaft that supports the distributor above the nozzle. The orifice itself is generally radially outwardly spaced from the shaft hole in the orifice plate. Representative examples of this type of construction are found in U.S. Pat. Nos. 4,967,961; 4,932,590; 4,842,201; 4,471,908; and 3,131,867. Other arc adjustment techniques are described in U.S. Pat. Nos. 5,556,036; 5,148,990; 5,031,840; 4,579,285; and 4,154,404.
It is also known to incorporate adjustable flow rate arrangements in sprinklers, within the context of a substantially constant water pressure. For example, see U.S. Pat. Nos. 5,762,270; 4,898,332; and 4,119,275. Such arc adjustment and flow rate adjustment features are often incorporated in pop-up sprinklers. Examples of pop-up sprinklers are found in U.S. Pat. Nos. 5,288,022; 5,058,806; 4,834,289; 4,815,662; and 4,790,481.
There remains a need, however, for a reliable sprinkler that incorporates an arc adjustment and/or a throw radius adjustment feature, and that provides constant precipitation rate and good uniformity, without excess leakage in the nozzle area.
There is also a need to provide a sprinkler head that permits reorientation of a fixed edge of the sprinkling pattern after the sprinkler has been fixed to an otherwise non-rotatable support, such as a riser tube in a pop-up sprinkler system. With one edge fixed, the nozzle could then be manipulated to adjust the movable edge of the pattern-defining opening as needed to produce the desired pattern. This feature may also be utilized with a nozzle designed to produce a fixed sprinkler pattern (for example, a rectangular pattern), where it is desirable to locate one edge of the pattern next to a wall, fence or the like.
The present invention relates to a sprinkler designed especially (but not exclusively) for incorporation in pop-up type sprinklers, and that provides within limits, essentially infinite arc adjustment and throw radius adjustment features, while at the same time, providing constant precipitation rates and good uniformity. The invention also provides a sprinkler that minimizes suckback plugging of the nozzle; permits active cleaning of the nozzle, and minimizes potential damage to critical internal components when, for example, impacted during use.
In one exemplary embodiment, the sprinkler head itself includes a nozzle, a rotary water distribution plate (or rotor plate) mounted on a shaft so as to be axially spaced from the nozzle. The rotor plate is formed with a plurality of curved, generally radial grooves that cause the rotor plate to rotate when impinged upon by a hollow, generally cone-shaped stream emitted from the nozzle. The rotor plate may incorporate a viscous damping mechanism to slow its rate of rotation.
In the pop-up embodiment, the nozzle and associated stream deflector are supported within a hollow stem which, in turn, is supported within a cylindrical base. A coil spring is located axially between a flange at the upper end of the stem and an arc adjustment ring at the upper end of the base. This coil spring biases the rotor plate, shaft, nozzle, deflector and stem to a retracted position relative to the base.
The shaft on which the rotor plate is mounted extends downwardly into and through the deflector, and is provided with an externally threaded sleeve fixed to the lower end of the shaft. A throttle member is threadably mounted on the fixed sleeve, but is prevented from rotating, so that rotation of the shaft will result in the throttle member moving axially upwardly or downwardly on the shaft, depending on the direction of rotation of the shaft, toward or away from a stop formed near the lower end of the stem. The invention also provides a “slip clutch” mechanism to protect the stem assembly in the event of over-rotation of the shaft.
The throw radius adjustment mechanism in the exemplary embodiment is implemented by flow rate adjustment via the throttle member, but, preferably, the arrangement is such that the flow cannot be completely shut off. In other words, even in a position where the throttle member is moved to its maximum restrictive position on an associated stop (and to thus provide the smallest throw radius), enough water is permitted to flow through the base to the nozzle so that the rotor plate continues to rotate, albeit at a slower speed. This preferred configuration is intended to prevent stalling, a condition where the rotor plate ceases rotation as water pressure drops. The flow rate and hence throw radius adjustment is effected by rotation of the shaft by a suitable tool engageable with an end of the shaft that is externally accessible to the user. Aside from the flow rate adjustment function, the shaft is otherwise rotationally stationary during normal operation, i.e., the rotor plate rotates about the shaft.
In accordance with this continuation-in-part application, the throttle member is constructed of a suitable urethane rubber and preferably a polyurethane thermoplastic elastomer. Using this material, the interior surface of the throttle member may be left smooth when manufactured, but will resiliently self-tap when engaged by the externally threaded sleeve fixed to the lower end of the shaft. This arrangement is particularly advantageous in that, in the event the shaft is over-rotated, the elastomeric throttle member will simply slip over the thread on the shaft sleeve, thus creating an effective “slip clutch” that prevents damage to the stem assembly.
The nozzle is rotatably mounted within the base, and cooperates with the stream deflector to define an arcuate water discharge orifice. The nozzle is operatively connected through a drive mechanism to the arc adjustment ring mounted on the top of the base, and externally accessible to the user. Thus, the user may rotate the arc adjustment ring to lengthen or shorten the arcuate length of the discharge orifice. It is presently contemplated that a pair of nozzle/deflector combinations may be employed to provide adjustable arcs between 90° and 210°, and between 210° and 270°. In accordance with another embodiment, the nozzle and deflector are further modified to provide a 360° or full circle pattern, and for this embodiment no arc adjustment is possible. Nevertheless, this latter embodiment may still include the above described flow rate adjustment feature. In the full circle version, the nozzle and stream deflector are modified, but all other components are retained, some to good advantage. The arc adjustment ring, for example, may be rotated to loosen and effect removal of debris lodged in the nozzle, without otherwise altering the arc of coverage.
The arc adjustment feature can be utilized only when the rotor plate is extended relative to the base. In other words, components of the drive mechanism are fully engaged only when the nozzle, deflector and stem move upwardly with the rotor plate to engage complementary drive components on the arc adjustment ring. This arrangement prevents accidental arc adjustment when the sprinkler is not in use, e.g., through contact with a lawn mower, weed trimmer or the like. In addition, the arc adjustment ring is configured to permit re-orientation of the sprinkler pattern after the sprinkler is secured to, for example, a fixed, non-rotatable stem or riser in a pop-up assembly.
The rotor plate may also incorporate a known viscous dampening type “motor” (or “viscous retarder”) that slows the rotation of the rotor plate, thereby increasing the throw radius of the stream.
When used in a pop-up type sprinkler, the invention employs a two-stage pop-up mechanism. First, the extendable tube of the pop-up assembly will extend as water under pressure is introduced into the assembly. After the tube extends out of the fixed riser, the rotor plate, nozzle, deflector and stem extend away from the base at the distal end of the extendable tube so that water emitted from the nozzle can be distributed radially by the rotor plate. This two-stage action is reversed when the flow of water is shut off, so that the rotor plate is in a retracted position that prevents any foreign matter from entering into the nozzle area before the extendable tube of the pop-up assembly is retracted.
The arc adjustment ring and the extendable tube are configured such that the application of sufficient torque to the arc adjustment ring in either an opening or closing direction results in the movement of the normally fixed internal edge that determines one end of the pattern arc. When the fixed edge is located as desired, the arc adjustment ring may be rotated in the opposite direction to enlarge or reduce the pattern, by moving the adjustable edge toward or away from the fixed edge until the desired arc is obtained.
Thus, in accordance with one aspect of this continuation-in-part application, the invention relates to a sprinkler head comprising a base; an elongated stem having an inlet supported within the base; a nozzle supported within the stem and adapted to emit a stream; a shaft extending through the base, one end of the shaft having an externally threaded sleeve thereon; and an elastomeric throttle control member constructed with a smooth through-bore, engaged over the externally threaded sleeve but prevented from rotating such that rotation of the shaft causes the throttle control member to move axially relative to a flow restriction portion in the inlet, to thereby adjust flow rate through the stem and the nozzle.
In another aspect, the invention relates to a sprinkler head comprising a base; an elongated stem having an inlet supported within the base; a nozzle supported within the stem; a water distribution plate supported on one end of a shaft extending upwardly from the base, the water distribution plate located in axially spaced relationship to the nozzle and adapted to be impinged by a stream emitted from the nozzle; an externally threaded sleeve fixed to an opposite end of the shaft; and an elastomeric throttle control member constructed with a smooth through-bore, engaged over the externally threaded sleeve but prevented from rotating such that rotation of the shaft causes the throttle control member to move axially relative to a flow restriction portion in the inlet, to thereby adjust flow rate through the stem and the nozzle.
In still another aspect, the present invention relates to a sprinkler head comprising a base; a nozzle and a stream deflector supported within the base; a nozzle and a stream deflector supported within the base, the nozzle having a first moveable edge and deflector having a second normally fixed edge cooperating to define an adjustable arcuate discharge orifice; a water distribution plate supported on a shaft extending upwardly from the base, the water distribution plate having a plurality or water distribution grooves therein locate din axially spaced relationship to the nozzle and adapted to be impinged by a stream emitted from the nozzle; an arc adjustment ring rotatably mounted on the base, the arc adjustment ring operatively connectable with the nozzle for rotating the nozzle and first movable edge relative to the stem and second normally fixed edge for adjustment of the arcuate discharge orifice; means operable through the arc adjustment ring for adjusting the second normally fixed edge to reorient the sprinkling pattern; an externally threaded sleeve fixed to the shaft; and an elastomeric throttle control member constructed with a smooth through-bore, engaged over the externally threaded sleeve but prevented from rotating such that rotation of the shaft causes the throttle control member to move axially relative to a flow restriction portion, to thereby adjust flow rate through the nozzle.
A detailed description of the invention follows in connection with the attached drawings that are identified below.